Wednesday, November 30, 2011

How many of you have heard the name Dr. Andrew Wakefield? His uber-small, sample study that linked childhood vaccines to autism was retracted by the British Medical Journal. Why is this important? This study fueled the fire for many people choosing not to immunize. But really, what harm is it not to immunize your child against common childhood diseases? You can read about this retraction and the impact it has by following this link: http://www.cnn.com/2011/HEALTH/01/05/autism.vaccines/index.html

I want to introduce a concept to you. It's called herd immunity. I can already see index fingers flying up, scratching a few temples. Cows? She's talking about cows? This girl has lost her mind-- been working too many 12 hour shifts.

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Malibu56/Photobucket

﻿﻿﻿﻿Let me explain. Herd immunity is the number of immunized individuals in a group (be it people or cows). It affords certain protection if the "herd" is largely immunized. Let me paint a scenario for you. Take a population of 100 people. Now, 99 of them are immunized against measles. There is a measles outbreak in the next town five miles over. Measles is highly contagious. What's the chance of measles taking hold in this community where 99% of individuals are immunized? What if the herd immunity in that town was 80%. What are the chances then?

In this scenario, the likelihood of measles taking hold in the community where 99% of people are immunized is low. Dr. Paul Offitt, in his book, Deadly Choices, states that likely 95% herd immunity will protect a community against measles. In 2008, the following states all had immunization rates <70%: Washington, Vermont, Idaho, Montana and Nevada. The likelihood of a measles outbreak taking hold in those state is high.
In the article above concerning Dr. Wakefield, it lists some of the ramifications of people choosing not to immunize.

"The now-discredited paper panicked many parents and led to a sharp drop in the number of children getting the vaccine that prevents measles, mumps and rubella. Vaccination rates dropped sharply in Britain after its publication, falling as low as 80% by 2004. Measles cases have gone up sharply in the ensuing years."

The 95% herd immunity for measles seems to hold true.

"In the United States, more cases of measles were reported in 2008 than in any other year since 1997, according to the Centers for Disease Control and Prevention. More than 90% of those infected had not been vaccinated or their vaccination status was unknown, the CDC reported."

But really, what's the problem with a case of measles? Why did they invent that vaccine anyway? You can read more about measles infection on the following links but one possible complication of measles infection is encephalitis (1:1000 measles cases). I was a little shocked by that number. Encephalitis is an infection in the brain.

The main concern with measles is that it is highly contagious. There is no "cure" once a case is contracted, merely symptomatic support. Measles is very concerning if a pregnant woman contracts it. Read the following:

"If you're not immune to rubella and you come down with this illness during early pregnancy, it could be devastating for your baby. You could have a miscarriage or your baby could end up with multiple birth defects and developmental problems. Congenital rubella syndrome, or CRS, is the name given to the pattern of problems caused when a baby is born with the virus."

I think the following paragraph lends support to the point of having high herd immunity when it come to measles.

"Rubella has become quite rare in the United States, thanks to a very successful vaccination program. Before the rubella vaccine was developed in 1969, a rubella epidemic in 1964 and 1965 caused 12.5 million cases of the disease and 20,000 cases of CRS in the United States. In contrast, between 2001 and 2005, there were a total of 68 reported cases of rubella and five reported cases of CRS. And in 2006, there were just 11 reported cases of rubella and only one case of CRS."

How often do you hear this side when it comes to the immunization debate? What good is this for fiction? I talked to a pediatrician in our area and asked him what his current rates of immunization were. He stated he was lucky to have 50% of his kids immunized. Some of those children are now women of childbearing age. I think it would be easy to add as a pregnancy complication for any story. What about a measles outbreak?

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The medical information presented on this blog is for writers to use in their works of fiction. If a medical question is submitted, it is assumed that it is for a current work of fiction and not related to an actual person’s medical problem. Consult a licensed physician for specific information, advice and treatment related to a medical condition.